Turbine oil compositions

ABSTRACT

A lubricating oil composition, particularly suitable for use in steam turbines or gas turbines, is disclosed. The turbine oil composition comprises a major amount of a mineral or synthetic hydrocarbon base oil and an effective amount of a combination of the following materials: triphenyl phosphite or a trialkylsubstituted phenyl phosphite; diphenylamine or alkylated diphenylamine; phenyl Alpha -naphthylamine, phenyl Beta naphthylamine, alkyl or alkaryl substituted phenyl Alpha naphthylamine, or alkyl or alkaryl substituted phenyl Beta naphthylamine; benzotriazole or alkyl-substituted benzotriazole; partial ester of alkyl or alkenyl succinic anhydride. In a preferred aspect, the turbine oil composition contains additionally an effective amount of a copolymer of N-vinyl-2pyrrolidone and an Alpha -olefin.

United States Patent 11 1 Durr, Jr. et al.

[ Dec. 2, 1975 TURBINE OIL COMPOSITIONS Okla.

[73] Assignee: Continental Oil Company, Ponca City, Okla.

[22] Filed: Oct. 7, 1974 [21] Appl. No: 512,765

I52] US. Cl. 252/49.9; 252/50; 252/5l.5 A; 252/78; 252/79 [51] Int. Cl. ClOM 1/10; ClOM 3/02; CiOM 5/02;

Primary Examiner-Delbert E. Gantz Assistant Examiner-l. Vaughn Attorney, Agent, or FirmBayless E. Rutherford, Jr.

[57] ABSTRACT A lubricating oil composition, particularly suitable for use in steam turbines or gas turbines, is disclosed. The turbine oil composition comprises a major amount of a mineral or synthetic hydrocarbon base oil and an effective amount of a combination of the following materials: triphenyl phosphite or a trialkyl-substituted phenyl phosphite; diphenylamine or alkylated diphenylamine; phenyl a-naphthylamine, phenyl ,B-naphthylamine, alkyl or alkaryl substituted phenyl a-naphthylamine, or alkyl or alkaryl substituted phenyl B-naphthylamine; benzotriazole or alkyl-substituted benzotriazole; partial ester of alkyl or alkenyl succinic anhydride. [n a preferred aspect, the turbine oil composition contains additionally an effective amount of a copolymer of N-vinyl-Z-pyrrolidone and an a-olefin.

16 Claims, No Drawings TURBINE OIL COMPOSITIONS H BACKGROUND 1. Field of the Invention The invention is in the field of lubricating oils which are particularly suitable for use in gas turbine engines, including aircraft and automotive, and stationary steam turbine engines. i

2. General Background It is generally recognized that the operating conditions of gas turbine engines expose the lubricant to extreme conditions. In order to be satisfactory, the lubricant must be resistant to oxidation and corrosion at high temperatures. Moreover, the lubricant must be resistant to deposit-formation at high temperatures.

Normally, gas turbine and steam turbine units require different lubricant types, the former synthetic esterbased oils and the latter petroleum oils.

We have found a particular combination of lubricant additives which work in mineral lubricating oils or synthetic hydrocarbon lubricating oils. Furthermore, the lubricant compositions of our invention work in either steam turbines or gas turbines. They are particularly suitable for use in gas turbines. Because of this, our lubricant compositions provide an important advance in the art.

3. Prior Art Each of the lubricant additives used in our lubricant compositions is known to be useful in lubricating oils. However, we have found that certain synergistic relationships are present in the additives which provide improved results in the combinations used. For example, we have found that the lubricant compositions of the broad aspect of our invention provide superior performance, particularly when compared to commercially available products. While these compositions provide good overall test results, we have found that the addition of a small amount of the particular copolymer used in our invention provides a pronounced improvement in the test results. i i

BRIEF SUMMARY OF THE INVENTION Broadly stated, the present invention is directed to a lubricating oil composition which comprises a major amount of a mineral or synthetic hydrocarbon base oil and an effective amount of a combination of the following materials: triphenyl phosphite or a trialkyl-substituted phenyl phosphite; diphenylamine or alkylated diphenylamine; phenyl a-naphthylamine, phenyl ,8- naphthylamine, alkyl or alkaryl substituted phenyl anaphthylamine'or alkyl or alkaryl substituted phenyl ,B-naphthylamine; benzotriazole or alkyl-substituted benzotriazole; partial ester of alkyl or alkenyl succinic anhydride. a

In a preferred aspect, the lubricating oil composition contains additionally an effective amount of a copolymer of N-vinyl-Z-pyrrolidone and an oz-olefm.

The lubricating oil compositions of our invention have properties which render them particularly useful in steam or gas turbines.

Materials Used The base oil can be a conventionally refined mineral lubricating oil or a synthetic hydrocarbon lubricating oil. The mineral lubricating oils are well known to those skilled in the art. Both light viscosity (e.g., pale oils) and heavy viscosity (e.g., bright stock) oils can be used. A complete description of mineral lubricating oils is 2 provided by Nelsons Petroleum Refinery Engineering (McGraw-Hill, New York, 1958).

Suitable synthetic hydrocarbon lubricating oils include di-n-long-chain alkaryls, as described hereinafter, linear mono-olefin oligomers, and a composition consisting essentially of di-n-long-chain alkaryls and trialkyl-substituted tetrahydronaphthalenes.

Linear mono-olefin oligomers, which are suitable as lubricating oils, are described in several U.S. patents, e.g., U.S. Pat. Nos. 3,382,291, 3,149,178, and 3,808,134.

A particularly suitable linear mono-olefin oligomer composition is prepared from oz-olefins containing 6 to 16 carbon atoms, more suitably 8 to 12 carbon atoms, and preferably 10 carbon atoms. The linear mono-olefin oligomer composition contains at least 50 weight percent, more usually at least 60 weight percent, of materials containing 24 to 60 carbon atoms.

Theterm di-n-long-chain alkaryl refers to materials represented by the formula wherein R and R, are alkyl groups containing from 6 to 18 carbon atoms, more suitably from about 9 to about 15 carbon atoms, and preferably from about 10 to 14 carbon atoms, with the sum of R and R, being from about20 to about 28 carbon atoms and wherein A and A, are hydrogen or a C, or C alkyl group, but preferably are hydrogen. I

Thus, the preferred di-n-long-chain alkaryl is a di-nalkylbenzene wherein the alkyl group contains from about 10 to about 14 carbon atoms.

The alkyl groups are substantially straight-chain (thus the term n-alkaryls) wherein, preferably, at least 95 percent of the alkyl substituents are bonded to the benzene nucleus through a secondary carbon atom of the respective alkyl groups. While we prefer the term n-alkaryls, other terms such as linear alkaryls or straight-chain alkaryls are equally descriptive.

A particularly suitable di-n-long-chain alkaryl trialkyl-substituted tetrahydronaphthalene composition typically contains the following The composition is also characterized as having the following properties: i

Viscosity indcx -1 16 Pour Point. F 40 to -80 Molecular weight range 350-526 Preferably 375-480 The di-n-long-chain alkaryls meet the description provided in the foregoing.

The trialkyl-substituted tetrahydronaphthalenes can be represented by the formula wherein R and R contain from 1 to about 13 carbon atoms each, with the sum of R and R being from about 6 to about 14 and R and R contain from 1 to about 16 carbon atoms with the sum of R and R, being from about 9 to about 17. The alkyl groups, R R R and R are straight-chain.

The trialkyl-substituted tetrahydronaphthalenes have the same boiling range as the di-n-alkylbenzenes. In addition, they have approximately the same molecular weight.

Suitable phosphites include triphenyl phosphite and trialkyl-substituted phenyl phosphites, wherein the phenyl moiety has 1 or 2 alkyl substituents, each of which contains 1 to 12 carbon atoms. Examples of the latter-named phosphites which are suitable include triphenyl phosphite, tritolyl phosphite, tricresyl phosphite, trihexylphenyl phosphite, tributylphenyl phosphite, and tri (mixed monoand dinonylphenyl) phosphite. Tri (mixed monoand dinonylphenyl) phosphite is particularly suitable.

Suitable triazoles include benzotriazole and alkylsubstituted benzotriazoles having 1 or 2 alkyl groups containing 1 to carbon atoms, preferably 1 carbon atom. Benzotriazole is available under the trade name Cobratec 99 from Sherwin-Williams Chemical. A particularly suitable alkyl-substituted triazole is tolyltriazole which is available under the trade name Cobratec TT-lOO from Sherwin-Williams Chemical.

Suitable partial esters of an alkyl or alkenylsuccinic anhydride are the products obtained by the reaction of one molar equivalent of a polyhydric alcohol with two molar equivalents of the anhydride. Structurally, these materials are represented by the formula wherein of the radicals R and R, one is hydrogen and the other is an alkyl or alkenyl group containing from 8 to 15 carbon atoms and R" is the residue of the polyhydric alcohol which generically may contain oxygen, sulfur, or nitrogen in the chain as well as ester substituents, and preferably contains from 3 to 6 carbon atoms. The integer n represents a number from 1 to 4. In so doing, n includes, in the residue, derivatives of diols, triols, and other polyhydroxy compounds.

A preferred partial ester for use in our invention is represented by the formula wherein of R and R, one represents hydrogen and the other a branched chain dodecenyl group and R" is an alkylene group of 3 to 6 carbon atoms.

A commercially available partial ester which can be used in our invention is Hitec E-536, available from Edwin Cooper Company, St. Louis, Missouri.

The preparation of and additional information concerning these partial esters are provided by US. Pat. No. 3,1 17,901, which is made a part of this disclosure.

Tricresyl phosphate is a well known chemical, being represented by the formula (C H Me)PO Any high quality, commercially available tricresyl phosphate can be used.

Diphenylamine or alkylated diphenylamines containing 1 or 2 alkyl groups containing from about 4 to about 16 carbon atoms per group can be used in the compositions of our invention. The latter-named material is preferred. A suitable commercially available alkylated diphenylamine is Naugalube 438-L, available from the Chemical Division of UNlROYAL. This material is predominantly p,p'dinonyldiphenylamine. It has the following physical properties: Specific Gravity0.99; Flash Point350F; Viscosity, F, SU- S3900; Viscosity-2lOF-86 SUS.

Phenyl a-naphthylamine and phenyl B-naphthylamine are suitable for use in our invention. Preferred materials of this type are phenyl a-naphthylamine, or phenyl B-naphthylamine, having 1 or 2 alkyl or alkaryl substituents, each of which contains 1 to about 16, preferably about 6 to about 8, carbon atoms. A suitable commercially available material of the latter type is Naugalube 460-C, available from the Chemical Division of UNIROYAL. This material is a mixture of a major .amount of di-styrenated phenylbetanaphthylamine and a minor amount of mono-styrenated phenylbetanaphthylamine. It has the following typical properties: Specific Gravity-4.05; Percent Ash 0.l; Percent Nitrogen2.8-2.9.

The vinyl-pyrrolidone--a-olefin copolymers which are suitable for use in our invention are characterized as being the reaction product of N-vinyl-Z-pyrrolidone and 0.5 to 12 moles of an a-olefm containing 8 to 30 carbon atoms, preferably 18 to 22 carbon atoms. The materials have a molecular weight of about 2,000 to about 20,000, preferably 7,000 to 12,000. Details on the preparation and properties of the copolymers are provided in US. Pat. Nos. 3,296,134 and 3,423,381, which patents are made a part of this disclosure. The preferred copolymer is the reaction product of 1 mole of N-vinyl-Z-pyrrolidone and 1 mole of a C-20 a-olefin. An example of a commercially available preferred copolymer is Ganex V-220, which is available from GAF Corporation, West 51st Street, New York, New York. This material has the following physical properties:

Physical Form. 25C waxy solid Relative Viscosity 1 1.007 Density (2) 0.95 Average Molecular Weight (3) 8.600 Softening Point 30C Melting Range (4) Iii-36C l l 0.1 g/l00 l'l\l toluene used as solvent (2) gnilec at 231' (31 .\lolceul;tr netglit number tnerztge determined h High Speed ()smometer in toluene at 351' (-1) Determined on the Mannheim Block 6 Amounts of Materials Used i A IOO-ml test sample, on which viscosity in centi- The amounts of the various materials used in the turstokes at 100F and neutralization number have been bme o1l composmons of our invention, are shown bemeasured, issubjected to a temperature of 347F for a low, in both suitable and preferred ranges. period of 72 hours in the presence of 5 liters of air per 5 hour and polished, cleaned, weighed copper, silver, Amount steel, magnesium, and aluminum coupons held rigidly M in a specific arrangement. Mmcnu i Prcfmcd The test apparatus consists of a test tube (to contain gh ap t e 0.05-1.5 0.10 1.0 10 the test sample) which is fitted with vertical water- 1ti?disghit ti tii hen lamihe1 0.02-0.75 0.05-0.50 conqensepand air-delivery tube extendmg to PhcnyLnuphthyI-aminc 040-075 0154,35 within one-elghth inch of the bottom of the test tube. of AMI O-OUHHU (Hm-01130 The tube is submerged its entire length except for the or Alkeri yl SuCCiniL Anhydridc 0.02-0.50 0.05-0.10 joint and Condenser in a Constant temperature bath at P W of i test temperature. and M54 At the end of the test period specified, these observations and measurements are made and recorded:

As is implied, the balance of the composition is the Co en dep (l q of Solid) pp base lubricating oil, it being understood that other conb. Viscosity change, viscosity change from original vcntional lubricant additives can be included, if deat 100F, centistokes and neutralization number sired. change from original are determined on filtered oil. Use of Other Materials in Our Invention 0. Deposits or solids contained in oil sample, in test In describing our invention, we have shown only the Cell, and on coupons are collected on a filter paper essential materials which are used therein. It is to be and their weight determined to the nearest 0.1 mg.

understood that other conventional lubricating oil ad- 7 d. Metal coupons are washed and weighed to estabditives can be used in the composition, if desired. Exlish loss or gain to the nearest 0.1 mg.

LII

amples of other such materials include, but are not lime. Deposits adhering to test cell after scraping and ited to, antifoam agents, pour point depressants, viscoshing are ated for appearance in vapor, Oil-air ity and viscosity index improvers, and dyes. interface, and bottom of test cell.

In order to disclose the nature of the present inven- 20 A e tability test as used to measure Cu-Pb beartion still more clearly, the following examples, both iling corrosion. Briefly, this test can be described as follustrative and comparative, will be given. It is to be unlows: derstood that the invention is not to be limited to the A copper-lead faced steel coupon, 1 X 3 inches, is

specific conditions or details set forth in these examples cleaned in accordance with the established procedure except insofar as such limitations are specified in the 3 and weighed. Two hundred milliliters of test sample is appended claims. 5 placed in a 400-ml tall form beaker. The test coupon is Test Methods placed in the beaker, which is then covered with a The test methods used to evaluate the various comwatch glass, and placed in a 250F oven for 96 hours.

positions, both illustrative and comparative, were the At the end of the specified period of time the beaker is following: removed and allowed to cool. The coupon is removed,

1. Federal Test Method 5308.6 of Standard 791 b. 40 washed with hexane, dried, and weighed. 2. Rotary Bomb Oxidation Test ASTM-D-2272 In the following examples the materials used were as 3. ASTM-D-943 Oxidation Test follows. Base oils X and Y were mineral lubricating 4. Heat Stability Test oils. Also, both base oils were pale oils. Base oil X had Inasmuch as the first of these tests are standard, puba viscosity of I00 SSU- at 100F, while base oil Y has a lished tests, it is not believed necessary that they be deviscosity of 170 SSU at 100F.

crib d h r in, The materials, other than base oils, used in the com- Since the data from the Federal Test Method 5308.6 positions tested were as follows: was used more consistently, this test will be described in some detail. Usually in this test, the only values obo Triazolc Cobratcc" tamed are 01] viscosity change, acid number change, Phosphitc Triphenyl Phosphitc and the weight loss of the metal test specimens. In addiuHlcc" B536.

Antifoam Agent Commercially available s1l1conc tron to these values, we obtamed the amount of SOlIdS Alkylatcd diphcnyl amine Ndtt rrluhv 438-L deposited or formed during the test. This value is exg i -fir s g gpressed as milligrams of solids per grams of oil 1 Gmex sample. In our opinion, this value is a good indicator of the tendency to cause residues in operation of a tur- The amounts of the various materials used in the bme, wh1ch, in turn, can lmpair performance. 7 compositions tested, stated in weight percent, were as A description of Federal Test Method 5308.6 folfollows: lows:

COMPOSITION N0. Material A B c 1) E F o H 1' TriuZOlC 0.02 r 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 Phosphitc 0.24 0.12 0.12 0.24 0.24 0.12 0.12 0.12 Purtlul Ester 0.0a 0.0x 0.08 0.08 0.08 0.08 0.0x 0.00 Anllfuam Agent 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Alkylatcd diphcnylaminc 0.014 0.08 0.10 0.08 0.0x 0.0x 0.0x 0.0x Phcnyl-B-naphthylaminc i 0.25 0.50 1 0.25 0.25 0.50 0.25 0.25 0.25 Copolymcr i I (H5 Base Oil Base ()il 8923' 8910 $9.27 89.48 89.3l 89.22 89.35 89.43 39.22

The results of the tests on Compositions A-E are shown in Table 1 following while the test results on Compositions F-l are shown in Table 11. For purposes of comparison, the results of tests on a commercial high A comparison of the test results on Compositions A+H with the test results on the commercial oils shows that the latter are inferior to Compositions AH. Of Compositions A-H, Composition G is considered to temperature Oi (understoo as Suitable fOr use in g have the best overall properties. A comparison of the turbmes) and a yp Steam turbme 011 are PrOVlded test results on Composition 1, which contains addition- Table ally the copolymer, with Composition G shows that TABLE 1 COMPOSITION A 1) E Results: FTM 5308.6-72 Hr Vis. CS at 100F-Orig 34.98 35.32 35.09 34.67 35.07 -Final 36.58 36.74 37.41 40.24 38.96 Vis. Change 1.6 1.42 2.32 5.57 3.89 /1 v15. Change 4.6 4.0 6.6 16.1 11.1 Neut. No.-Original 0.44 0.33 0.33 0.39 0.49 $16.11 1.06 1.31 1.97 2.91 2.07 Ncut. No. Change 0.62 0.98 1.64 2.52 1.58 Corrosion, Mg/coupon Silver +3.7 +0.2 +0.5 +2.4 +1.7 Copper +2.1 +0.8 +1.5 +2.7 +1.5 Steel +2.9 +0.3 +0.7 +3.2 +2.4 Magnesium +3.2 +0.4 +0.6 +4.0 +3.0 Aluminum +3.4 +0.6 +0.5 +4.3 +2.6 Deposits Vapor Lt Lt Lt Med Lt-Mcd lnterfacc Hvy Hr Hvy Hvy Med Filtered-Mg/IOO grns. 180 270 385 609 364 Oil appearance Miscellaneous Results Cu-Pb Brg-96 hrs at 250F (1) Wt. Chg.-Mg/Coup0n +53.1 +260 +255 +593 +493 RBOT at 150C-minutcs 745 695 525 650 500 l Heat Stability- Test TABLE 11 COMPOSITlON F o H 1 Results: 5308.6-72 Hr Vis. CS at 100F-Orig. 35.45 35.11 36.1 35.31 -Fln2.\l 40.63 40.4 39.86 36.39 Vis. Change 5.18 5.29 3.74 1.08 '71 v15. Change 14.6 15.1 10.4 3.1 Neut. No.-Original 0.11 0.33 0.1 l 0.27 -Final 1.68 1.86 2.30 1.41 Ncut. No. Change 1.57 1.53 2.19 1.1-1 Corrosion. Mg/coupon Silver 0.0 +0.3 +5.7 0.5 Copper +0.8 +1.2 +1.0 +0.6 SlCCl +0.2 +0.4 +0.6 +0.1 Magnesium +1.0 +0.6 3.1 +0.1 Aluminum +0.4 +0.5 +0.6 0.0 Deposits Vapor Lt Lt Lt-Mcd Tr Interface Hvy Med Med Tr Filtercd-Mg/IOO gms. 527 472 450 122 Miscellaneous Results Cu-Pb Brg-96 Hrs at 250F l) Wt. Chg.-Mg/coupon l6.4 4 +17.1 +0.5 RBOT at 150C-minutes 540 565 595 330 1 Heat Stabilit Test TABLE I11 Composition 1 provides better corrosion results, better mber re- Typicul commercial v1scos1ty results, and better neutral12at1on nu Steam High Temp. sults. It follows that Composition l.g1ves better test rechunctcrstc Pwpcmcs Turbmc sults than the commercial oils. The data supports this Water Emulsion O-W-E-T 40-40-0-30 39-38-3-60 tat m t, 'g' ff Fs A fif 4 000 600 Thus, having described the invention in deta1l, 1t w1ll M 1 T be understood by those skilled in the art that certam 5: 1;! 5g +17 M +5 8 variations and modifications may be made without delSC. C- I {r No +535 partmg from the sp1r1t and scope of the 1nvent1on as de- Cwwsiom s P fined herein and in the appended cla1ms.

Silver +2.0 +1.9 Copper We claim:

.1 I l vlflz ncsium Hi7 1. A turbine Oll compos1t1on compnsmg a ma or Aluminum amount of a mineral or synthetic hydrocarbon base lug yss g' F 313. H 1 bricating oil and the following combination of matenals Ll LUl'll'l S 96 Hrs. M Wt. Change/Coupon +3.4 0.2 in the amounts spec1f1ed as we1ght percent of total RBOT at C. Minutes 405 40(35) composition:

a. about 0.05 to about 1.5 -triphenyl phosphite or trialkyl-substituted phenyl phosphite having 1 or 2 alkyl substituents, each of which contains 1 to 12 carbon atoms;

b. about 0.02 to about 0.75 diphenylamine or alkylated diphenylamines containing :1 or 2 alkyl groups, on one or both phenyl moieties, containing from about 4 to about 16 carbon atoms,

c. about 0.10 to about 0.75 phenyl a-naphthylamine, phenyl ,B-naphthylamine, phenyl a-naphthylamine having 1 or 2 alkyl or alkaryl substituents, each of which contains 1 to about 16 carbon atoms, and phenyl B-naphthylamine having 1 or 2 alkyl or alkaryl substituents, each of which contains 1 to about 16 carbon atoms;

(1. about 0.002 to about 0.10 -benzotriazole or alkylsubstituted benzotriazoles having 1 or 2 alkyl groups containing 1 or 2 alkyl groups containing 1 to carbon atoms; and

e. about 0.02 to about 0.50 -partial ester of an alkyl or alkenyl succinic anhydride, which is represented by the formula wherein of the radicals R and R, one is hydrogen and the other is an alkyl or alkenyl group containing from 8 to carbon atoms, R" is a residue of a polydric alcohe] containing from 3 to 6 carbon atoms, and n is an in- 5. The turbine oil composition of claim 1 wherein the base lubricating oil is a synthetic hydrocarbon lubricant which is selected from the group consisting of di-nlong-chain alkaryls, linear mono-olefin oligomers, and a composition consisting essentially of di-n-long-chain alkaryls and trialkyl-substituted tetrahydronaphthalenes, wherein a. the term di-n-long-chain alkaryls refers to materials represented by the formula wherein R and R, are substantially straight-chain alkyl groups containing from 6 to 18 carbon atoms, with the sum of R and R, being from about 20 to about 28 and wherein A and A, are hydrogen or a C, or C2 alkyl group,

b. the term linear mono-olefin oligomer refers to materials prepared from a-olefins containing 6 to 16 carbon atoms and which contain at least 50 weight percent of materials containing 24 to 60 carbon atoms, and

c. the term trialkyl-substituted tetrahydronaphthalenes refers to materials represented by the formula wherein R, and R are straight-chain alkyl groups containing from 1 to about 13 carbon atoms each, with the sum of R, and R being from about 6 to about 14, and wherein R and R, are straight-chain alkyl groups containing from about 1 to about 16 carbon atoms, with the sum of R and R, being from about 9 to about 17.

6. The turbine oil composition of claim 5 wherein it contains about 0.05 to about 1.50 weight percent of a copolymer of 1 mole of N-vinyl-Z-pyrrolidone and 0.5 to 12 moles of an a-olefin containing 8 to 30 carbon atoms.

7. The turbine oil composition of claim 6 wherein it contains a copolymer of about 1 mole of N-vinyl-2-pyrrolidone and about 1 mole of a C a-olefin.

8. A turbine oil composition comprising a major amount of a mineral or synthetic hydrocarbon base lubricating oil and the following combination of materials in the amounts specified as weight percent of total composition:

a. about 0.10 to about 1.0 triphenyl phosphite or tri (mixed monoand dinonylphenyl) phosphite;

b. about 0.05 to about 0.50 diphenylamine or alkylated diphenylamine which is predominantly p,p-dinonyldiphenylamine;

c. about 0.15 to about 0.35 phenyl a-naphthylamine, phenyl B-naphthylamine or a substituted phenyl B-naphthylamine which is a mixture of a major amount of di-styrenated phenyl B-naphthylamine and a minor amount of mono-styrenated phenyl ,B-naphthylamine;

(1. about 0.005 to about 0.030 benzotriazole or toly ltriazole;

e. about 0.05 to about 0.10 partial ester of an alkyl or alkenyl succinic anhydride, which is represented by the formula wherein of the radicals R and R, one is hydrogen and the other is an alkyl or alkenyl group containing from 8 to 15 carbon atoms, R" is a residue of a polydric alcohol containing from 3 to 6 carbon atoms, and n is an integer of at least one but less than 5.

9. The turbine oil composition of claim 8 wherein the base lubricating oil is a mineral oil.

10. The turbine oil composition of claim 9 wherein it contains about 0.10 to about 0.80 weight percent of a copolymer of 1 mole N-vinyl-Z-pyrrolidone and 0.5 to 12 moles of an oz-olefin containing 8 to 30 carbon atoms.

11. The turbine oil composition of claim wherein it contains a copolymer of about 1 mole of N-vinyl-Z- pyrrolidone and about 1 mole of a C a-olefin.

12. The turbine oil composition of claim 8 wherein the base lubricating oil is a synthetic hydrocarbon lubricant which is selected from the group consisting of di-n-long-chain alkaryls, linear mono-olefin oligomers, and a composition consisting essentially of di-n-longchain alkaryls and trialkyl-substituted tetrahydronaphthalenes, wherein a. the term di-n-long-chain alkaryls refers to materials represented by the formula wherein R and R are straight-chain alkyl groups containing from l to about 13 carbon atoms each, with the sum of R and R being from about 6 to about 14, and wherein R and R, are straight-chain alkyl groups containing from about 1 to about 16 carbon atoms, with the sum of R and R being from about 9 to about l7.

13. The turbine oil composition of claim 12 wherein the partial ester of succinic anhydride is represented by the formula wherein of R and R one represents hydrogen and the other a branched chain dodecenyl group and R" is an alkylene group of 3 to 6 carbon atoms.

14. The turbine oil composition of claim 13 wherein it contains about 0.10 to about 0.80 weight percent of a copolymer of 1 mole N-vinyl-2-pyrrolidone and 0.5 to 12 moles of an a-olefin containing 8 to 30 carbon atoms.

15. The turbine oil composition of claim 14 wherein it contains a copolymer of about 1 mole of N-vinyl-2- pyrrolidone and about 1 mole of a C olefin.

16. The turbine oil composition of claim 15 wherein the base lubricating oil is a composition consisting essentially of di-n-long-chain alkaryls, which are present in an amount of 61 to 92 weight percent, and trialkylsubstituted tetrahydronaphthalenes which are present in an amount of 5 to 30 weight percent. 

1. A TURBINE OIL COMPOSITION COMPRISING A MAJOR AMOUNT OF A MINERAL OR SYNTHETIC HYDROCARBON BASE LUBRICATING OIL AND THE FOLLOWING COMBINATION OF MATERIALS IN THE AMOUNTS SPECIFIED AS WEIGHT PERCENT TOTAL COMPOSITION: A. ABOUT 0.05 TO ABOUT 1.5 -TRIPHENYL PHOSPHITE OR TRIALKYLSUBSTITUTED PHENYL PHOSPHITE HAVING 1 OR 2 ALKYL SUBSTITUENTS, EACH OF WHICH CONTAINS 1 TO 12 CARBON ATOMS; B. ABOUT 0.02 TO ABOUT 0.75 DIPHENYLAMINE OR ALKYLATED DIPHENYLAMINES CONTAINING 1 OR 2 ALKYL GROUPS, ON ONE OR BOTH PHENYL MOIETIES, CONTAINING, FROM ABOUT 4 TO ABOUT 16 CARBON ATOMS; C. ABOUT 0.10 TO ABOUT 0.75 PHENYL A-NAPHTHYLAMINE, PHENYL B-NAPHTHYLAMINE, PHENYL A-NAPHTHYLAMINE HAVING 1 OR 2 ALKYL OR ALKARYL SUBSTITUENTS, EACH OF WHICH CONTAINS 1 TO ABOUT 16 CARBON ATOMS, AND PHENYL B-NAPHTHYLAMINE HAVING 1 OR 22 ALKYL OR ALKARRYL SUBSTITUENTS, EACH OF WHICH CONTAINS 1 TO ABOUT 16 CARBON ATOMS; D. ABOUT 0.002 TO ABOUT 0.10 -BENZOTRIAZOLE OR ALKYL-SUBSITUATED BENZOTROAZOLES HAVING 1 OR 2 ALKYL GROUPS CONTAINING 1 OR 2 ALKYL GROUPS CONTAINING 1 TO 10 CARBON ATOMS; AND E. ABOUT 0.02 TO ABOUT 0.05 PARTIAL ESTER OF AN ALKYL OR ALKENYL SUCCINIC ANHYDRIDE, WHICH IS REPRESENTED BY THE FORMULA
 2. The turbine oil composition of claim 1 wherein the base lubricating oil is a mineral oil.
 3. THE TURBINE OIL COMPOSITION OF CLAIM 2 WHEREIN IT CONTAINS ABOUT 0.05 TO ABOUT 1.50 WEIGHT PERCENT OF A COPOLYMER OF 1 MOLE N-VINYL-2-PYRROLIDONE AND 0.5 TO 12 MOLES OF AN A-OLEFIN CONTAINING 8 TO 30 CARBON ATOMS.
 4. The turbine oil composition of claim 3 wherein it contains a copolymer of about 1 mole of N-vinyl-2-pyrrolidone and about 1 mole of a C20 Alpha -olefin.
 5. The turbine oil composition of claim 1 wherein the base lubricating oil is a synthetic hydrocarbon lubricant which is selected from the group consisting of di-n-long-chain alkaryls, linear mono-olefin oligomers, and a composition consisting essentially of di-n-long-chain alkaryls and trialkyl-substituted tetrahydronaphthalenes, wherein a. the term di-n-long-chain alkaryls refers to materials represented by the formula
 6. The turbine oil composition of claim 5 wherein it contains about 0.05 to about 1.50 weight percent of a copolymer of 1 mole of N-vinyl-2-pyrrolidone and 0.5 to 12 moles of an Alpha -olefin containing 8 to 30 carbon atoms.
 7. The turbine oil composition of claim 6 wherein it contains a copolymer of about 1 mole of N-vinyl-2-pyrrolidone and about 1 mole of a C20 Alpha -olefin.
 8. A turbine oil composition comprising a major amount of a mineral or synthetic hydrocarbon base lubricating oil and the following combination of materials in the amounts specified as weight percent of total composition: a. about 0.10 to about 1.0 - triphenyl phosphite or tri (mixed mono- and dinonylphenyl) phosphite; b. about 0.05 to about 0.50 - diphenylamine or alkylated diphenylamine which is predominantly p,p''-dinonyldiphenylamine; c. about 0.15 to about 0.35 - phenyl Alpha -naphthylamine, phenyl Beta -naphthylamine or a substituted phenyl Beta -naphthylamine which is a mixture of a major amount of di-styrenated phenyl Beta -naphthylamine and a minor amount of mono-styrenated phenyl Beta -naphthylamine; d. about 0.005 to about 0.030 benzotriazole or tolyltriazole; e. about 0.05 to about 0.10 partial ester of an alkyl or alkenyl succinic anhydride, which is represented by the formula
 9. The turbine oil composition of claim 8 wherein the base lubricating oil is a mineral oil.
 10. The turbine oil composition of claim 9 wherein it contains about 0.10 to about 0.80 weight percent of a copolymer of 1 mole N-vinyl-2-pyrrolidone and 0.5 to 12 moles of an Alpha -olefin containing 8 to 30 carbon atoms.
 11. The turbine oil composition of claim 10 wherein it contains a copolymer of about 1 mole of N-vinyl-2-pyrrolidone and about 1 mole of a C20 Alpha -olefin.
 12. The turbine oil composition of claim 8 wherein the base lubricating oil is a synthetic hydrocarbon lubricant which is selected from the group consisting of di-n-long-chain alkaryls, linear mono-olefin oligomers, and a composition consisting essentially of di-n-long-chain alkaryls and trialkyl-substituted tetrahydronaphthalenes, wherein a. the term di-n-long-chain alkaryls refers to materials represented by the formula
 13. The turbine oil composition of claim 12 wherein the partial ester of succinic anhydride is represented by the formula
 14. The turbine oil composition of claim 13 wherein it contains about 0.10 to about 0.80 weight percent of a copolymer of 1 mole N-vinyl-2-pyrrolidone and 0.5 to 12 moles of an Alpha -olefin containing 8 to 30 carbon atoms.
 15. The turbine oil composition of claim 14 wherein it contains a copolymer of about 1 mole of N-vinyl-2-pyrrolidone and about 1 mole of a C20 olefin.
 16. The turbine oil composition of claim 15 wherein the base lubricating oil is a composition consisting essentially of di-n-long-chain alkaryls, which are present in an amount of 61 to 92 weight percent, and trialkyl-substituted tetrahydronaphthalenes which are present in an amount of 5 to 30 weight percent. 